Croydon Council is to launch a campaign warning about the risk of sexually transmitted infections.
The two-week campaign see posters displayed around the borough urging people to get tested and use contraception.
The posters will feature a QR code that can be scanned by mobile devices to access more information.
The campaign will launch on Tuesday, August 12.
Councillor Louisa Woodley, cabinet member for people and communities, said: "It’s very easy for people to get tested and clearly we want more people to do so for their own sexual health and that of other people.
"However it’s also easy to think that you don’t need to get tested as you have no symptoms.
"This is the message we want to spread – you could have an STI without even knowing.
"Therefore it’s really important."
Visit swish.nhs.uk, call 020 8401 3002 or speak to your GP for free confidential advice on sexual health.